Front-end
Network
Back-end

This talk is about

1.

Network compression

HTTP compression is a must-have

  • Up to 80% compression,
    especially for HTML
     
  • gzip is super popular,
    but try Brotli or Deflate
     
  • Beware of BREACH attacks,
    no problem with static files

2.

Better media
compression

SVG, AVIF, WebP, WebM

Better options than JPEG and PNG 

  • Media files are often the most heavy requests
     
  • Use SVG whenever you can
     
  • Use AVIF / WebP / PNG mix otherwise

  •  

3.

Mastering
Cache

Browser Cache, BDD Cache, Proxy Cache, Local Cache...

Different layers of cache

BDD Cache

Service
Cache

Proxy
Cache

Browser
HTTP Cache

Local Cache
localStorage
Cache API
IndexedDB...

All caches are useful
Think ahead
how can you use them ?

4.

Replacing UMD/CJS by ESM


Dead code elimination / Tree shaking

Always use ESM

  • Static definition for the win
     
  • Enables dead code elimination
    (tree-shaking)

5.

Bundling & Code Splitting
done right

6.

Targeted

transpilation


with browserslist

7.

Agressive
Transpilation


babel "loose" mode

8.

Minification
done right

9.

User-specific
externalized
polyfills


with polyfills.io

10.

Modern mode

module / nomodule

10.

Modern mode

module / nomodule

11.

Performance
budgets

import costs

12.

Non-blocking

rendering

CSS Critical Path

Web fonts swap

13.

Preloading

& Prefetching

14.

Preloading
on mouseover

InstantClick, InstantPage...

15.

Server-Side
Rendering

16.

Optimistic UI

a.k.a.
Latency Compensation

 

17.

Functional
Programming
pure functions &
low-level optimizations

18.

Do not block
the thread

using Web Workers
 

19.

Perf audits
CPU/memory dumps

using Dev Tools
 

20

ways to
improve
performance
of  your webapps

20 ways to improve web performance

By sylvainpv

20 ways to improve web performance

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